Chapter 3, Problem 56A

(a)

Interpretation Introduction

Interpretation: The formula of substance containing 1 C atom and 2 O atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the molecule contains 1 C atom and 2 O atoms. The number of valence electrons in C atom is 4 and that in O atom is 6. Oxygen atom requires 2 electrons to complete its octet and C requires 4 electrons.

The C atom forms covalent bonds by sharing of 2 electrons with each O atom. This results in the formation of two double bonds. The molecule so formed will be ${\text{CO}}_{\text{2}}$ .

Thus, formula of molecule containing 1 C atom and 2 O atoms will be ${\text{CO}}_{\text{2}}$ .

(b)

Interpretation: The formula of substance containing 1 Al atom and 3 Cl atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the compound contains 1 Al atom and 3 Cl atoms. Here, Al is a metal and it can give 3 electrons to form ${\text{Al}}^{3+}$ ions. On the other hand, Cl is a non-metal and it can take 1 electron to form ${\text{Cl}}^{-}$ . Thus, 1 Al atom forms compound with 3 Cl atoms and the formula of compound will be ${\text{AlCl}}_{\text{3}}$ .

Thus, formula of compound containing 1 Al atom and 3 Cl atoms will be ${\text{AlCl}}_{\text{3}}$ .

(c)

Interpretation: The formula of perchloric acid containing one H atom, one Cl atom and four O atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the perchloric acid contains 1 H atom, 1 Cl atom and 4 O atom. Here, Cl will be the central atom and H atom will be at terminal position.

Since, it is an acid thus, H should be ionizable and there must be 1 −OH group.

The number of valence electrons of Cl is 7 thus, it can form covalent bonds (double bond) with the remaining 3 O atoms. Here, Cl atom has extended octet.

Thus, formula of perchloric acid will be ${\text{HClO}}_{\text{4}}$ .

(d)

Interpretation: The formula of molecule containing 1 S atom and 6 Cl atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the compound contains 1 S and 6 Cl atoms. The number of valence electrons in S is 6 and that in Cl atom is 7. Cl atom can take 1 electron to complete its octet thus, 1 S can form 1 covalent bond each with 6 Cl atoms to form compound with extended octet of S.

The formula of compound will be ${\text{SCl}}_6$ .

Explanation of Solution

As per the given information, the molecule contains 1 C atom and 2 O atoms. The number of valence electrons in C atom is 4 and that in O atom is 6. Oxygen atom requires 2 electrons to complete its octet and C requires 4 electrons.

The C atom forms covalent bonds by sharing of 2 electrons with each O atom. This results in the formation of two double bonds. The molecule so formed will be ${\text{CO}}_{\text{2}}$ .

Thus, formula of molecule containing 1 C atom and 2 O atoms will be ${\text{CO}}_{\text{2}}$ .

(b)

Interpretation Introduction

Interpretation: The formula of substance containing 1 Al atom and 3 Cl atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the compound contains 1 Al atom and 3 Cl atoms. Here, Al is a metal and it can give 3 electrons to form ${\text{Al}}^{3+}$ ions. On the other hand, Cl is a non-metal and it can take 1 electron to form ${\text{Cl}}^{-}$ . Thus, 1 Al atom forms compound with 3 Cl atoms and the formula of compound will be ${\text{AlCl}}_{\text{3}}$ .

Thus, formula of compound containing 1 Al atom and 3 Cl atoms will be ${\text{AlCl}}_{\text{3}}$ .

(c)

Interpretation: The formula of perchloric acid containing one H atom, one Cl atom and four O atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the perchloric acid contains 1 H atom, 1 Cl atom and 4 O atom. Here, Cl will be the central atom and H atom will be at terminal position.

Since, it is an acid thus, H should be ionizable and there must be 1 −OH group.

The number of valence electrons of Cl is 7 thus, it can form covalent bonds (double bond) with the remaining 3 O atoms. Here, Cl atom has extended octet.

Thus, formula of perchloric acid will be ${\text{HClO}}_{\text{4}}$ .

(d)

Interpretation: The formula of molecule containing 1 S atom and 6 Cl atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the compound contains 1 S and 6 Cl atoms. The number of valence electrons in S is 6 and that in Cl atom is 7. Cl atom can take 1 electron to complete its octet thus, 1 S can form 1 covalent bond each with 6 Cl atoms to form compound with extended octet of S.

The formula of compound will be ${\text{SCl}}_6$ .

Explanation of Solution

As per the given information, the compound contains 1 Al atom and 3 Cl atoms. Here, Al is a metal and it can give 3 electrons to form ${\text{Al}}^{3+}$ ions. On the other hand, Cl is a non-metal and it can take 1 electron to form ${\text{Cl}}^{-}$ . Thus, 1 Al atom forms compound with 3 Cl atoms and the formula of compound will be ${\text{AlCl}}_{\text{3}}$ .

Thus, formula of compound containing 1 Al atom and 3 Cl atoms will be ${\text{AlCl}}_{\text{3}}$ .

(c)

Interpretation Introduction

Interpretation: The formula of perchloric acid containing one H atom, one Cl atom and four O atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the perchloric acid contains 1 H atom, 1 Cl atom and 4 O atom. Here, Cl will be the central atom and H atom will be at terminal position.

Since, it is an acid thus, H should be ionizable and there must be 1 −OH group.

The number of valence electrons of Cl is 7 thus, it can form covalent bonds (double bond) with the remaining 3 O atoms. Here, Cl atom has extended octet.

Thus, formula of perchloric acid will be ${\text{HClO}}_{\text{4}}$ .

(d)

Interpretation: The formula of molecule containing 1 S atom and 6 Cl atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the compound contains 1 S and 6 Cl atoms. The number of valence electrons in S is 6 and that in Cl atom is 7. Cl atom can take 1 electron to complete its octet thus, 1 S can form 1 covalent bond each with 6 Cl atoms to form compound with extended octet of S.

The formula of compound will be ${\text{SCl}}_6$ .

Explanation of Solution

As per the given information, the perchloric acid contains 1 H atom, 1 Cl atom and 4 O atom. Here, Cl will be the central atom and H atom will be at terminal position.

Since, it is an acid thus, H should be ionizable and there must be 1 −OH group.

The number of valence electrons of Cl is 7 thus, it can form covalent bonds (double bond) with the remaining 3 O atoms. Here, Cl atom has extended octet.

Thus, formula of perchloric acid will be ${\text{HClO}}_{\text{4}}$ .

(d)

Interpretation Introduction

Interpretation: The formula of molecule containing 1 S atom and 6 Cl atoms needs to be determined.

Concept introduction: The formula of the molecule depends on the number of atoms present in the given molecule. It also depends on the valence electrons of atoms to know the exact ratio of number of moles of atoms present in the molecule.

As per the given information, the compound contains 1 S and 6 Cl atoms. The number of valence electrons in S is 6 and that in Cl atom is 7. Cl atom can take 1 electron to complete its octet thus, 1 S can form 1 covalent bond each with 6 Cl atoms to form compound with extended octet of S.

The formula of compound will be ${\text{SCl}}_6$ .

Explanation of Solution

As per the given information, the compound contains 1 S and 6 Cl atoms. The number of valence electrons in S is 6 and that in Cl atom is 7. Cl atom can take 1 electron to complete its octet thus, 1 S can form 1 covalent bond each with 6 Cl atoms to form compound with extended octet of S.

The formula of compound will be ${\text{SCl}}_6$ .